I tried the RME FF400 for a time but for several reasons I let it go. The main reasons were
1. The inputs into the FF400 dramatically change the sound of the source.
2. It's not balanced across the full range of frequencies.
3. The inputs are noisy.
4. The pre's for mics aren't very good.
Despite being well constructed with plenty of ins/outs, a good front panel control dial, good software I thought it sounded harsh. So what's the point in having it.
One test I did was to compare the output from my Neve 8801 (using the Neve's headphone out) against the RME's line inputs being fed by the Neve which I then monitored from the RME's headphone out. There was a significant difference in the sound. The RME seemed to be louder in the mid's and lacked definition in the lows and introduced alot of noise. It wasn't being faithful to the output from the Neve and I got rid of it.
Anyway I changed to the Orpheus and now what comes out of the Neve, or any source for that matter, is identical to what goes into the DAW, no change in the sound at all. I couldn't be happier with the upgrade.
Cheers, Dave